For those who are interested, here is a brainteaser that took me more than15 mins to solve (apologies to those who don't think it belongs here, andto the person I pinched it from)

On the Isle of Reason live exactly 50 logicians. There are no otherinhabitants. Each day they all meet to discuss riddles and life. Howeverthere is one topic they do not discuss. On each of their foreheads is ablue dot. However it is so shameful to have a blue dot, that knowing thisfact for a certainty, will certainly result in the bearers' suicide thenext morning. For this reason blue dots and related things are NEVERdiscussed. Fortunately there are no mirrors or reflections on the islandand so everyone is blissfully unaware of the blue dot they have, but cansee the other 49 blue dots....until, one day a visitor to the island comesand knowing something of the strange problems of the island thinks he willbe tactful and announces "I happen to have noticed that at least one of youhas a blue dot on his forehead". He leaves the island unaware of whatfollows. Precisely fifty nights pass and on the next morning all fiftylogicians commit suicide. Why?

Note: there is sufficient information in the riddle, it is not a play onwords and can be solved by pure logic. The fact that they discuss riddlesis irrelevant. They could come together each day without a word beingspoken!

Finally, for those who have heard the riddle, answer this. Why does someoneneed to come to the island and say that there is a blue dot? Surely each ofthem can see 49 other dots and knows that there is a blue dot? The answermust be as tight as the answer to the riddle!